1. Field of the Invention
The present invention relates to a spacer forming method used for a biosensor, and more particularly a biosensor having a spacer constructed by thick-film printing technology. The present invention also relates to the structure of the biosensor that is made in accordance with this spacer forming method.
2. Description of Related Art
Several disposable biosensors were developed to determine the different substances in the human body fluid. Especially, the glucose strip is the best application example of the disposable biosensor, and this product has become an important medical device for the diabetics to monitor their blood glucose away from hospital. To monitor the glucose levels frequently is a fact of everyday life for diabetic individuals, and a number of glucose meters are now available which permit the individual to test the glucose level in a small amount of blood.
For the convenience of applying a blood sample and using small amount of blood, it is useful to use the capillary sampling method to quantitatively introduce the very small amount of sample into a reaction area. The construction of capillary sample channel needs a spacer component to provide the wall of the sample channel, and the adhesion of a sheet with a specific thickness on the biosensor is the most popular method found in the conventionally commercial strip. Examples of device of this type were disclosed in U.S. Pat. No. 5,120,420; U.S. Pat. No. 5,288,636; and U.S. Pat. No. 5,437,999 which are incorporated herein by reference.
The conventional biosensor is usually constructed by adhering the spacer component onto the base plate in a position relative to the electrode. However, the use of this method to constrict the spacer component causes a serious problem in the punching process because a glue sheet is adhered to the mold and this affects the precision of punching element, and slows down the throughput.
Additionally, in the general electrochemical glucose meter, a micro switch is embedded in the connector. An expensive and complex connector has to be developed but the connectors can""t identify whether the inserted strip is up side or not. Furthermore, the micro switch is usually used to be a trigger switch instead of the power switch, and the battery power still supplies the static current to the circuits when the strip is withdrawn from the meter. Therefore, the connecting of micro switch does not shut down the meter completely, and the extra power consumption occurs when the meter is idle. According to the above description, the conventional biosensors still have drawbacks and thus there is need for an improved biosensor.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional biosensor.
A first objective of the present invention is to provide a spacer forming method used for a biosensor to make the manufacturing process for the biosensor effective. By means of stainless stencil printing technology, a spacer layer is constructed to be the wall of the sampling channel and a sample application port is controlled by adjusting the thickness of the printed pattern.
A second objective of the present invention is to provide a spacer forming method used for a biosensor, wherein the biosensor reduces sample demands and introduces a sample reagent into a reaction layer precisely and rapidly by the capillary sampling channel.
A third objective of the present invention is to provide a spacer forming method used for a biosensor, wherein the biosensor eliminates several adhering steps by constructing a uniform spacer layer so as to simplify the production process and meet the requirement of accuracy.
A fourth objective of the present invention is to provide a spacer forming method used for a biosensor, wherein an actuating strip is printed on the same side of electrodes on the biosensor so as to control the electric states of the biosensor.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.